Method of forming billets



Oct. 28, 1941. v M. L. STRAWN 2,260,351

METHOD 'OF FORMING BILLETS' 3 Original Fil'ed Feb. 8, 1937 QTTQIQ I P 11911 8 dldm, in which- Patented ooi. 28,1941

UNITED STATE S PATENT OFFICE mop or some mars Marion L. strawmkooklord Ill, asaignor to The Ingerso Milling ll MachineOompany ord, ill, a corporation oi Illinois Application February 8, 1981, Serial No. 124,640

' Renewed March 21, 1940 I v 1 claim. (01. ss-isao- The invention relates tom'e'tal billets. commonly known as wire bars, and to an improved method'oi making the same.

I In making wire of copper or the like, thegen eral procedure consists oi casting a'wire bar or billet, parsing the'wire bar through a series oi rolls to reduce ita cross'section by elongating the same, thenznnally'v extruding the elongated blank throughJsuitable-wire drawing dies.

Preparatory-to the rolling and drawing operations, itls desirable to remove from the ends oi the cast billet any metal containing slag or other imperiections and avoid any resulting sharp edges which. might cause cracks or other imperfections tobe' formed in the finished wire as an incident tothe rolling and drawing operations,

It-hasheretoiore been the practice to cast copper wire bars in either horisontal open iace molds or in vertical opentop molds. .The use of open top molds is desirable in that the area oi the suriace oi-molten metal exposed to oxidation is minimized and the metal has a nner crystalline 'structure.- On the other hand. such an open top mold produces a barwithfa relatively flat upper end portion-which impurities and as cast is unsuited ior 'properflltry-between the reducing roils.- lieretoioreg have been preend. portion and then'am sthe ends into a tapered shape. or mechanical creates fracture -so that-thewire drawn -.;irom the swsged metal b apt to be weakero'r containimperfections.

preparing metal bars oi the above. character.

Other objects and advantages oi the invention will become apparent ioilowing detailed description taken inconnection with the accom- Figure lis'aslde viewoiafvertically castwire Piss. 2 and 3 are-side views wire bar orbillet oi the iorln contemplated by the present inventiom. Fig; 4 is-an enlarged alons h l Hinl'ig.8.

Fig. 5 is' a longitudinal sectional view oi one endoi the billet illustrating the steps oi preparing the same ior rolling.

while the invention is susceptible oi various modifications and alternative constructions. I

have shown in the drawing and will herein describe in detail the preferred embodiment, but it 0! an improved view iaced mold, and in addition, shaped to round or bevel the longitudinal edges the invention by such disclosure but aim to cover all modifications and alternative constructions ialling within the spirit and scope of the invention as expressed inthe appended claim.

In accordance with the present invention, a

rough vertically cast billet in (Fig. lloi copper or the like is prepared for drawing by fashioning the same to iorm the novel wire bar or billet ll exemplified in Figs. 2 .and 3. Upon reference to Fig. 1, it will be seen that the rough billet I0 is elongated in form and generally rectangular-in oi the billet.

pared ior roiling by oil the oxidized nieinvention reside'a'in the novel method oi In general, improved vertically cast billets of the novel iorm contemplated by the present in-- vention have tapered ends free of sharp edges; and iurther have a comparatively homogeneous crystalline structure from end to end without weaknesses due to localized mechanical working. Thus, the finished billet Ii has tapered end portions ll oi truncated pyramidal shape terminating in blunt rounded end surfaces It which will enter the rolls properly.

The sides It! oi the pyramidal ends it are preierably formed the correspondin as planar 'continuations oi sides 0 oi the bar in order first to minimize theamount oi metal which is bar or billet prior-to the periormanoe oi any shaping operations thereon.

the iinished bar.

cast metal blank in iorming I Secondly, the suriaces it automatically cooperate with the rolls by which the size oi the billet is reduced to automatically square up the body portion oi thev billet with reierence to the rolls. As a result oithis coaction between the rolls and the tapered end as the latter enters between the rolls. the main removed from the body oi the billet always isied into the rolls in the proper angular position. The corner suriaces oi the tapered ends are beveled or rounded as best shown at it in Fig. 4 and merge with thesuriacestsothattherearenoedges the finished her having suflicient'sharpness to develop. into cracks or other the rolling operations.' v

I is to be understood that 1 do not intend to limit It herein contemplated,

; In accordance with the improved method imperiections in the slagend i: oi the wire bar or billet ii is fashioned in the desired shape I bya machining or metal-removing operation such as milling as distinguishedirom swaging or other mechanical working processes, so that there will be no localized mechanical working strains in th resultant product. In other words, the wire bar it will have a substantially homo-v geneous crystalline structure from end to end and will, in addition, be free oi oxide. Despite the fact that the wire bar is shaped by a metalremoving operation, a minimum amount of metal is cut from the blank in view of the improved pyramid-shaped taper which is preferably used.

Preferably, tapering of the ends and removal of the slag containing metal is effected by removing the metal in a succession of layers by a milling cut- Thus, as shown in Fig. 5,-cuts on any one side of the billet are taken along'dotted lines I I parallel to the surfaces Iii to be formed so as to remove metal layers 5 8 and form the tapered end. This method of machining is advantageous in that the number vof revolutions of relative rotation between the cutter and the billetin order to form the desired taper is reduced to a minimum. In addition, the layers 59 may be removed simultaneously during removal of the final layers ii. If desired, the surfaces I3 and the beveled or rounded surfaces 115 may be formed in the same milling operation. by means of a properly shaped milling cutter, successive layers is are removed from the end of the tapered portion until all of the slag containing metal is removed.

Then.

The opposite end portion oithe billet which is formed in the lower end of the mold. usually with a squared end it, may be tapered in a similar way in order to remove anyso-called cold shots that result. from splashing and premature solidification oi the molten metal initially discharged into the mold. In this instance, however, only enough metal need be removed from the extreme end of the pyramid to part the desired shape to the end surface it and at the same time insure complete removal oi the cold shots. a

By leaving such a rounded or generally eonvex surface 14 on the ends. objectionable flowing of the metal during the rolling operations and the consequent formation of a so-called tail at the endo'f the billet is efiectually avoided. The necessityof cutting oflj part of the end of the reduced billet in the course of rolling and a substantial waste of metal are thus elimi-- nated. I

- I claim as my invention: Y

The method of preparing a vertically cast billet for rolling and wire drawing which in cludes the steps of removing successive parallel layers of metal from the slag end of the billet to form a truncated pyramid with beveled edges, and separately removing successive curved layers of slag containing metal from the end of said pyramid to leave a oonvexly curved end surface.

MARION L. STRAWN. 

